Exclusive: After US pulls out of northern Syria, former Defense Sec. Mattis tells @chucktodd that "ISIS will resurge" if the US doesn't keep up the pressure. "It's absolutely a given that they will come back."

Exclusive: After US pulls out of northern Syria, former Defense Sec. Mattis tells @chucktodd that "ISIS will resurge" if the US doesn't keep up the pressure.

"It's absolutely a given that they will come back." https://t.co/u2mGUD9crp

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— NBC News (@NBCNews) October 13, 2019